The present invention related to a method for fabricating a semiconductor device, and more particularly, to a semiconductor device having a vertical channel and a method for fabricating the same.
Channels in semiconductor devices include recess, bulb, and fin type channels to expand the dimensions or length of the channel. However, while such semiconductor devices may have sufficient length or other dimensions of the channel, complex patterns have to be formed and cell efficiency has to be taken into consideration.
More specifically, in a semiconductor device having channels extended in a vertical direction with source and drain regions formed in upper and lower portions of pillar patterns, the pillar patterns may collapse and subsequently result in leaning of the pillar patterns.
FIGS. 1A, 1B, 1C, and 1D illustrate micrographic views of a typical semiconductor device having vertical channels. Referring to FIGS. 1A and 1B, collapse of pillar patterns are denoted with a reference numeral 11. Referring to FIGS. 1C and 1D, leaning of pillar patterns is denoted with a reference numeral 12.
Such undesirable formations may act as factors that deteriorate characteristics of a semiconductor device.